1. Field of the Invention
The present invention relates to an accounting method for sharing charges for services of a communications network with an originating user and/or a receiving user. The communications network to which the present invention is applied is a communications network in which the service charges for the use thereof are imposed and includes any kinds of communications networks such as an analog telephone network-and a data communications network like a packet communications network and an ISDN (Integrated Services Digital Network).
2. Description of the Related Art
In recent years, there have been developed data communications services via a data communications network such as a packet communications network and an ISDN. In such data communications services, as in the same way with the communications services via an analog telephone network, there is adopted a "connection-oriented" communications system that a data path is preset before data communications take place. FIG. 32 is a time arrow diagram showing a call setting sequence in this conventional communications system. Note that the network is illustrated in the form of one point in FIG. 32. As a matter of fact, however, this network is constructed of a plurality of switches and trunk lines for relaying these switches in all directions.
Now, the originating terminal transmits a calling message designating a specific receiving terminal to the network. Hereupon, the network selects a proper relay switch and trunk line in accordance with pieces of information on a subscriber's number of the receiving terminal which is contained in the calling message. The network thus sets a communications path (hereinafter simply termed a "path") ranging from the originating terminal to the receiving terminal. Subsequently, the network transfers a call-in message to the receiving terminal via this path and, at the same time, notifies the originating terminal of a fact that the path led to the receiving terminal has been set by sending back a call setting accept message. The receiving terminal sends back a response message to this call-in message to the network. Hereupon, the network sends back a response acknowledgement message to the receiving terminal and, at the same time, transfers a response message to the originating terminal via the set path. With the above sequence, a call is set, whereby the data communications become serviceable.
According to the accounting system of the charges (talk charges) for services of the communications network in the above-mentioned "connection-oriented" communications system, normally, the communications network service charges (talk charges) are calculated based on a quantity of receiving cells on the receiving user, and the charges are imposed on the originating user. Further, in the analog telephone network, there is spread a "collect call service" in which the communications network service charges (talk charges) are imposed on the receiving user with an agreement between the originating and receiving users when setting the call. Moreover, an accounting system wherein the charges are imposed on both of the originating user and the receiving user in accordance with a fixed rate is proposed (see Japanese Patent Laid-Open Publication No.61-146059).
By the way, for instance, if the originating and receiving users offer information exhibiting high added values to each other, it is rational that the (originating and receiving) users themselves flexibly determine a share of burden of the communications network service charges in accordance with a high-and-low balance of the added values of the information offered by each other.
In the conventional accounting system, however, the originating or receiving user is able to only determine which user is burdened with the charges but can not arbitrarily set a sharing rate thereof. Accordingly, the users do nothing but accept the burden of irrational communications network service charges. Note that there is caused such troublesomeness that the communications network service charges have to be cleared off between the users in an ex-post-facto manner. This is a first problem inherent in the conventional accounting system.
Next, in the conventional accounting system, the accounting destination can be determined only when setting the call. Hence, even when there arises a necessity for changing accounting specification (an accounting destination and/or an accounting share) in the middle of the communications, the accounting specification have to be accepted as they are, or the call has to be reset on another occasion after temporarily releasing the call (disconnecting the line). This a second problem inherent in the conventional accounting system. Note that the second problem is conspicuous especially when executing a "call waiting function". More specifically, the call waiting function provided presently as a line switching added service of OSI protocol layer-3 is a function that an in-communications user holds an in-communications call and simultaneously reply to a new call-in when the user receives a call-in notice and, further, make switchable both of the in-communications call and an in-hold call. Then, according to the conventional accounting system, even when a call of the user whom the communication service charges are imposed on (normally, the originating user but the receiving user) when using the collect call services is held due to the call waiting function, the user has to accept the burden of the communications network service charges during the hold due to some convenience of the partner user. This is irrational. Even in this case, the accounting specification can be changed if the call is reset by releasing the call (disconnecting the line). If done so, however, there arises a contradiction that a significance of introducing the call waiting services disappears.